通过电子束熔化增材制造技术成形的Ti-6Al-4V合金，是重要的人体承重部位植入物用材料。两相界面区、晶界以及孪晶内的原子堆积结构对于材料的力学性能具有重要作用。在温度和外加载荷作用下，界面区两端材料的结构与性质存在差异，这些差异导致的热应力不同以及变形不协调和局部应力集中使得界面两端相粒子和晶粒内驻留滑移带或晶界、孪晶界及相界面处的原子堆积结构出现差异。通过计算理解变形作用下晶粒内与晶界区及相界面区内原子堆积结构演化的微观机理，对于获得强度高、塑韧性好的该类新型材料的结构设计和实验制备具有重要意义。本项目拟采用分子动力学方法对Ti-6Al-4V合金内不同取向晶粒及晶界结构演化、孪晶界结构演化、相界面区结构和其力学、热力学性质的关系进行详细比较研究，提出形成强结合和性能一致钛合金生物材料的设计思路。项目的成功实施有助于指导植入体材料的组织设计和工艺优化。

Electron beam melting(EBM)- additive manufactured Ti-6Al-4V has increaingly shown great potential for human hard tissue implant and repair materials in recent years. The microstructures and mechanical properties are greatly affeced by the atom packing in the interface regions, grain boundaries, and twin boundaries. Under temperature and external load, there exist differences of the structures and properties between the two sides of the interfaces. These differences result in the changes of the thermal stress, non coordinated deformation, and stress raisers, which contribute to the atom packing changes in the phase particles at the end of the interface, grains in slip zones, grain boundaries, twin boundaries, and the interface regions. The mechanism is investigated for the atom packing changes in the grains, grain boundaries, and interface regions under the deformation conditions. These are of great significance to structural design and experimenal built for the novel materials having high strength and good ductility. Molecular dynamics computations are performed to study the structural evolution in the different grains, grain boundaries, twin boundaries, and interface regions as well as the relationship between the properties of mechanics and thermodynamics and the structural evolution in detail. Design ideas are put forward for the Ti alloy biomaterials with strong coupling and consistent performance. The successful implementation of the project is helpful in microstructural design and process optimization of human implants.